"Social Evolution is Lamarckian" - Right, Wrong or Misleading?

Here are some recent comments on my work and that of my co-author, Thorbjørn Knudsen:

"Following Nelson and Winter (1982

) - with the notable, but for me difficult to understand exception of Hodgson and Knudsen (2006) - most of evolutionary economists appear to agree that in this sense, socioeconomic evolution is indeed partly Lamarckian." (Pelikan 2010)

Both statements are strictly wrong. Neither author seems to have read carefully either our 2006 paper on "Dismantling Lamarckism" in the Journal of Evolutionary Economics or our 2010 book Darwin's Conjecture. In both places we admit the possibility of processes where the acquired characters of an interactor (social phenotype) can affect its replicators (social genotypes). But we contend that it is misleading to describe this as Lamarckian.

Why? There are several steps to the argument - see below. But since both Pelikan and Mesoudi agree with Knudsen and myself that social evolution is essentially a Darwinian process, I do not have to repeat the additional arguments here that

(a) Lamarckism and Darwinism are not rivals, and

(b) if social evolution were Lamarckian then it also would have to be Darwinian (Hodgson and Knudsen 2006, 2010).

Instead we can focus here on why the "Lamarckian" label is misleading in the social context.

Step 1. What is Lamarckism?

In Hodgson and Knudsen (2006, 2010b) we consider various positions held by Lamarck and Lamarckians. We argue that it is reasonable to define Lamarckism as the inheritance of acquired characters. At least that is the meaning that we concentrate on.

One dog catches fleas and passes some of them to another dog. Is that Lamarckian inheritance? If so, the fleas must be regarded as an acquired character and their jumping from one animal to another must be treated as inheritance. Similar arguments must apply to a host of other phenomena such as catching a cold and contagious laughter. All those processes would qualify on similar grounds as Lamarckian.

But something is wrong here. Almost all biologists now deny that acquired characters can be inherited in the biological sphere and reject Lamarckism, but none of them would see the phenomena described in the previous paragraph as a challenge to the current consensus in biology. We are not saying that what is true in biology must be also true in social evolution. Our point is different.

As David Hull (1982) points out, more must be added to make the Lamarckian claim meaningful. Inheritance must be distinguished from infection or contagion. The extra ingredient must be the genotype-phenotype distinction or a relevant equivalent. It is only with such a distinction that inheritance can be properly defined and distinguished from catching colds or fleas.

The genotype-phenotype distinction was introduced in biology in the twentieth century, long after the deaths of Lamarck and Darwin. But it is necessary to understand this issue. In biology the genotype is the complete genetic coding of an organism, consisting of instructions to guide its development and responses in its environment. The phenotype is the actual organism as it develops.

Any infection or contagion immediately affects the phenotype, not the genotype. By contrast, the Lamarckian inheritance of acquired characters means that a development in a phenotype can affect its own genotype, by some presumed internal process. We know in biology that this does not happen, but that is not the point. The requirement is to establish the difference in principle between Lamarckian inheritance and contagion. This we have now done.

Several authors suggest the term replicator as a generalisation of genotype, and interactor as a generalisation of phenotype (Hull 1988, Brandon 1996). They are generalisations, so they would apply to social as well as biological evolution. A lot of work has recently gone in to defining a replicator.

Building on this legacy, Knudsen and I define the replicator as consisting of program-like bits of information, held by an interactor, that can represent adaptive solutions to problems and guide its development. An interactor is a relatively cohesive entity that hosts replicators and interacts with its environment in such a way as to lead to changes in the population of interactors and their replicators. Replication is the copying of replicators and is (in our terms) synonymous with inheritance. For more precise versions of these definitions see Hodgson and Knudsen (2010b).

Step 3. Identifying the Social Replicators (Genotypes) and Social Interactors (Phenotypes)

In order to consider and understand the possibility of Lamarckian inheritance we must first identify the replicators and interactors in the social domain. We must then consider the possibility that the acquired character of an interactor can affect its replicators.

Ideas (or memes) are considered by some as replicators. The social interactors could be individuals. As Hull (1982) points out, the passing of ideas (as replicators) from person to person would not be the inheritance of acquired characters because the ideas themselves have been defined as replicators and not characteristics. One of the problems with the meme concept is that it is unclear whether it is a replicator or an interactor.

The pragmatist approach of Charles Sanders Peirce, William James, John Dewey and Thorstein Veblen helps here. Pragmatism sees ideas as grounded on habits, which in turn are learned dispositions to behave in a particular way in particular circumstances.

Habits are hosted by individuals as their interactors. Further examples of social replicators include routines, by which we refer to dispositions within organisations to carry out sequences of actions. Routines are hosted by organisations as their interactors, and in turn are built on the habits of the individuals involved.

Step 4. Is Lamarckian Social Inheritance Possible? And Meaningful?

Ideas are either replicators or (features of) interactors. If they are features of interactors then the spreading of ideas from one interactor to another is an example of contagion, not Lamarckism. If ideas are replicators, then (as pointed out above) their diffusion is the copying of replicators rather than acquired characters. This again is not Lamarckism.

Consider the replication (copying) of habits. Someone teaches us a new language. We imitate and repeat. We are corrected. We repeat again. This goes on until are responses are ingrained in habit. Gradually the knowledge of the language is transferred from one person to another. The replicators are replicated.

But note that the process of habit replication relies on behavioural imitation. (The way in which habits of thought are copied is more complex; it relies on language and is discussed in Hodgson and Knudsen (2010b).) In all cases of habit replication, the mechanism of replication goes through the interactor. Unlike genes in biology, there is no direct copying from replicator to replicator.

At first sight this seems very Lamarckian because as we repeat the behaviour of our teacher we develop the appropriate habits, our acquired behaviour (copied from another) gets encoded in our own habits. Our habit replicators change because we acquire a behavioural characteristic. We have freely admitted that this Lamarckian link (from our behaviour to our habit) does exist (Hodgson and Knudsen 2006, 2010b).

But the indirectness of habit replication creates problems for the Lamarckian story. The Lamarckian link (from our behaviour to our habit) is a causal cul-de-sac. All it does is ensure that we retain the capacity to repeat the behaviour. The Lamarckian link plays no part itself in the inheritance process. This is very different from any imagined Lamarckian process in the biological sphere, where replicators get copied directly. That is another reason why the Lamarckian description in the social sphere is misleading rather than strictly wrong. Ironically, the Lamarckian concept is more appropriate for the biological sphere, despite its invalidity in that domain.

Similar arguments apply to the replication of organisational routines, because that process too is grounded on the replication of individual habits (see Hodgson and Knudsen 2006, 2010b).

Addendum: Why Lamarckian Inheritance May be Limited

There are additional arguments why Lamarckian inheritance, if it existed, would be limited. The introduction of too much Lamarckian influence would mean that much cognitive and extraneous noise would interfere with the tried and tested information in the replicators. In Hodgson and Knudsen (2008, 2010a, 2010b) we show that the generation of complexity in an evolving system depends critically on the minimisation of copy error. Too much Lamarckian meddling with genotypes and replicators would mean too much response to the accidental and superficial, rather than the enduring. Crucial information would be lost and the growth of complex outcomes would be more difficult.

The claim by many social scientists that social evolution is Lamarckian is a distraction from the compelling conclusion that it is Darwinian, and that Darwinian ideas can be helpful in understanding the processes. Lamarckism does not provide an adequate evolutionary framework and it is a red herring.

Geoff Hodgson

1 March 2011

References

Brandon, Robert N. (1996) Concepts and Methods in Evolutionary Biology (Cambridge and New York: CambridgeUniversity Press).